A blog designed to address the condom size issue in regards to the erect penis circumference.
The goal is to propose a perfect fit and match between the erect penis circumference and the condom size used.

Sunday, October 9, 2011

Correspondence between CAS and Penis sizeThe old saying is, women don't have penis envy, men do. And widespread pornography may have distorted the male self-image, as well as the poor marketing strategies used by condom makers, competing with the not nearly as adapted paradigm "SMALL, STANDARD, LARGE, XL".

Let's come back a bit to the bra analogy. Here, there is not such a concept. Bras are classified by objective numbers, and even if it is not as perfect as it could be, women choose bras, based on this measuring system.

Condomerie in Netherlands has created such a system, by first removing the hard measures (length, circumference) and replacing it with a circumference / length ranking: The CAS index (which stands for Condomerie Amsterdam Standard index). This should do the trick by removing a great deal of anxiety, especially among youngsters. Please go here for the full explanation: Condomerie CAS Index

Actually, the CAS index is even more accurate, as it takes into account:

- the condom circumference at the opening,- the condom circumference at 7cm from the opening,

- the thickness of the condom wall,- the condom length.

The CAS is then laid down this way: CAS 2 / 2 /.. / D, with letters, dots and numbers following the matching rule explained on the Condomerie web site.

I propose to match the CAS, which ranks condoms based on objective criteria, with the erect penis circumference (to simplify, I will take into account only the opening circumference of the condom).

Here is a simplified matching table between condom CAS and penis size:

Find your erect penis circumference in the proposed ranges, and simply pick the CAS and/or condom sizes that fit you well.
For example, a man with an erect penis circumference of 5.2in could use any condom whose CAS index is 7. A man with an erect penis circumference of 127mm could use any condom whose CAS index is 6.

Of course, the determination of the erect penis length would be necessary to complete the CAS index:
If the erect penis is e.g. 155mm and given that the condom thickness is standard at 0.06mm, the CAS would become for our last example CAS: 6 / 6 / .. / D

For example, the site http://www.sizepenis.org/ has a tool available to determine the penis girth distribution by age. At 15 years old, an erect penis of 9cm is located above roughly 49% of the 15 years old population and below 51%, which is absolutely normal.

This condom size, the smallest available on the market, will be the best fit for erect penis circomferences from 90mm to 103mm.

It can be used safely and confortably up to a 108mm erect penis circumference.

This condom size will be the best fit for penises of an erect circumference from 104mm to 108mm but can be used from 104mm to 112mm.NB: Of course, if a 45mm size condom is not available, this size can be used for an erect penis circumference of 94mm and above. But please be careful, the closer the condom size and the erect penis circumference, the higher the risk of slippage...

This is the standard condom size in UE.This condom size can be used for an erect penis circumference from 115mm to 124mm. But the best fit would be for erect penises with a circumference of 115mm to 120mm.

This is the standard condom size in US.This condom size can be used for an erect penis circumference from 117mm to 127mm. But the best fit would be for erect penises with a circumference of 117mm to 122mm.

They have a slightly conic shape. To be used by whoever has an erect penis circumference which is not below 114mm along the shaft (for extra safety). But theoretically, the base width determines the condom size, i.e. 54.

They have a conic shape. To be used by whoever has an erect penis circumference which is not below 114mm along the shaft (for extra safety). The penis head should not be below 130 mm circumference when erect. But theoretically, the base width determines the condom size, i.e. 56.

This condom size can be used for an erect penis circumference from 124mm to 134mm. But the best fit would be for erect penises with a circumference of 124mm to 128mm.

With the 57 condom size come the real large condoms. The average erect penis is too small to fit safely in such a condom. It is the responsibility of each individual to choose objectively its condoms, with safety in mind first.

This condom size can be used for an erect penis circumference from 126mm to 136mm. But the best fit would be for erect penises with a circumference of 126mm to 131mm.

Sunday, October 2, 2011

Condom perfect fit
The below chart reports the ratio between the erect penis circumference and the condom size, for every erect penis circumference to be met in the population and for the different condom sizes to be found in stores or internet.

On top of it, the condom size proposed best fit has been added as well as the cumulative repartition of the population by circumference (last 2 columns).

For example, a man with a 115mm erect penis circumference (30th percentile of the population) should wear a condom of 50mm. But he could wear a 49mm condom for extra safety, or a 52mm for extra comfort. 53 or 54mm would present an important risk of slippage and are not advised in this case.

A man with a 125mm erect penis circumference (60th percentile of the population) should wear a condom of 55mm. But he could wear any condom from 53mm to 56mm.

A man with a 135mm erect penis circumference (85th percentile of the population) should wear a condom of 60mm. But he could wear any condom from 57mm to 60mm.

So please, use this chart to preselect you condom size, depending on your own erect penis circumference. Please keep in mind that if other factors vary such as the thickness of the rubber for example, the proposed condom sizes could become not so relevant anymore.

The actual pressure and force on the penis depends on the relative circumferences of the penis and condom, the thickness of the rubber, and its elastic modulus.

So the thickness of the rubber and its elastic modulus being constant, the determination of the correct size depends only on the ratio between the penis and condom circumference. It has to be so that it is not unduly stretched (not comfortable), nor too loose (the pressure from the condom on the penis is not high enough, and the condom will slip).The text below from the Condomerie Web site (Condomerie CAS Index) proves the consensus in the scientific community:

The most important thing when looking for the best fit is the condom's circumference. A condom that's too large can easily slip off, but a condom that is too tight is uncomfortable and the risk of tearing is greater. The length of the condom isn't as important, but should be as close to the length of the penis as possible. The condom's thickness and elasticity can also make it less or more comfortable.

Below is the chart of circumference ratios for the actual existing condom sizes:**

*The condom size is often called the diameter, but in fact it is the semi-perimeter (width when flat). A 53mm condom is in fact a condom of 106mm circumference (33.74mm diameter).

**Each line of the chart corresponds to the ratio between the condom circumference and the average circumference of the scientific study.

The chart shows that a man with a 122mm circumference erect penis (Janssen study average) can use safely condoms of sizes 52, 53, 54 and 55. With a 52 one, it will be safer (no slippage risk whatsoever), but not as comfortable as a 55 one (but more risk of slippage).

This chart proves at least one thing: the manufacturers perfectly know the average erect penis circumference, because their standard size (52-53) are a perfect fit for the "standard" penis. Indeed following Gerofi analysis, the perfect ratio ranges between 10% and 20%.

Below 10%, the risk of slippage increases slowly until 5% then drastically. Especially because the erect penis is not always at its maximum erection level (level often measured by men).

Above 20%, discomfort feeling increases until 30% where the risk of breakage increases.

Following the same rule, here is a simplified matching table between condom and penis size:

Find your erect penis circumference in the proposed ranges, and simply pick the condom sizes that fit you well.For example, a man with an erect penis circumference of 5.2in could use any condom whose size is between 2.20 and 2.36in (flat width). A man with an erect penis circumference of 127mm could use any condom whose size is between 54 and 57mm (flat width).

Average erect penis circumference
Here is an example of irrelevant and misleading information:

Just under three thousand (2,936) men took part in a DUREX survey – most of them under 25 – from all over the world. They self-reported their erect length and circumference. Both length and circumference vary quite widely but, in each case, there is an average value and in this survey they were 163 mm (6.4 inches) for erect length and 133 mm (5.2 inches) for erect circumference.

This is typical of surveys released publicly with absolutely no scientific background nor interest. Why then? It is unclear why manufacturers would release such information.

Below you will find a collection of true scientific studies, ie. anybody can re-produce it following the exact same protocols.

* Are included in the scientific average only the studies where the medical staff did the measuring or ensured a proper training.** The average erect circumference was extrapolated from the measured erect width considering the penis is a cylinder.

So basically, true scientific studies, where medical staff are conducting, training and often performing the measurement, come short of up to 1cm (0.4in) compared with non-scientific internet surveys.

NB: I didn't report data for length as it is not really relevant for choosing the right condom. As an example though, the Wessel Study came up with the following results: Erect length: 128.9mm (sd 29.1mm), fat pad : 28.5mm (sd 15.9mm), Functional erect length (Erect length non pubic bone pressed plus fat pad): 157.4mm (sd 26.2mm). This last result is consistent with the Kinsey data. To finish with erect penis length, the average (obtained by pressing the ruler on the pubic bone) from the scientific studies* above, is 147.64mm (sd 19.78mm).

So the real average erect circumference, or average erect penis girth, is around 121-123 mm.

All men - thus women - were, are or will be condom users.
Men then face the same situation women do when buying bras. Unfortunately, the comparison stops here:
- Where women buy and wear bras based on straight facts (band and cup size with a pretty precise yet tricky way), men have no opportunity to use a correct measuring system. The Amsterdam condom shop Condomerie is trying to set a measuring sytem for condoms, but it is far from being widely applied and still has some drawbacks.
- Men are not as mature as women. It seems so difficult for men to face objectively the truth: either small, standard or big, men tend to try to fit their penises in the biggest possible condoms, with all associated risks of slippage...
- Condom manufacturers use this as a marketing weapon in two different ways:
- Use a non harmonized label system where the use of words like LARGE, XL, Extra-Large... surf on the men's lack of self-estim and confidence.
- They do not tell the truth about penis size, thus reinforcing the impression of many men, especially the younger ones, that they "do not fit".

Because of all these reasons, I will try to import some objective figures into this subject, especially about erect penis circumference, and propose a way to determine the best fitting condom size.